When an original equipment manufacturer (OEM) installs an absorption device in a particular piece of equipment, it is necessary that the device have damping characteristics that are specifically suited for the particular equipment application. For example, an absorption device used to decelerate a small, lightweight pallet on a conveyor system would have different damping characteristics than an absorption device used to decelerate a large, heavy pallet on a larger conveyor system.
Conventional absorption devices are known wherein the resisting force setting of the device is preset for a particular application; no adjustment by the OEM is possible. This makes it impossible to mass produce a "generic" absorption device that can be selectively tuned by an OEM for various different equipment applications.
Adjustable absorption devices have been known wherein the OEM can adjust the resisting force setting of the device to suit the needs of a particular equipment application. U.S. Pat. Nos. 4,709,791 and 5,598,904, owned by the same assignee as the present application, disclose such an absorption device. Other conventional absorption devices have been known that enable the OEM to adjust the resisting force setting of the absorption device during installation, and then lock the device at the desired setting.
However, in both cases the end user of the equipment can unlock the device and adjust the resisting force of the absorption device, thus resulting in the possibility that the device later will be misadjusted for a particular application to the point where the absorption characteristics of the absorption device are ineffective for the particular application.
It would be desirable to provide an energy absorption device that allows the OEM to select the resisting force setting of the device to meet the particular requirements of the equipment on which the device is installed, lock the device at that setting, and then render the device tamper-proof as to the end user of the equipment.